If you're talking about the power adapter, you can buy a reputable one (it's external to the scope).
If you're talking about measurements on 220V equipment, just buy a genuine Digilent (or other brand) probe with 10x attenuation for about $20, then you can have complete faith in that the scope electronics will only see signals < 48V, which is completely safe.
You talk like you trust quite much in Digilent. I'll keep it in mind when looking for some instrumentation. Thanks a lot!
After it is well tested (measuring temperatures is hard, but doable) and you are confident it works, you can use it normally.
Anyway, I really encourage you to doing DIY projects at home. Most of them work in low voltages between 5 and 3.3V, risks are close to nothing.
Che, no te importa si cuelgo de tu wifi, o sí?
Oiga! Yo le subo wifi, usted baje unas chelas fresquitas! :p
I've bought a DSO138 DIY Oscilloscope Kit clone in eBay and I'm scared to connect it to 220V main line because I've not reliable information or safety warranties (It's a clone, not the DYE Tech certified one).
Not everybody cares about safety as they should.